Aafia Siddiqui is shown after her graduation from Massachusetts Institute of Technology. / AP

by Oren Dorell, USA TODAY

by Oren Dorell, USA TODAY

BOSTON - The mosque attended by the two brothers accused in the Boston Marathon double bombing has been associated with other terrorism suspects, has invited radical speakers to a sister mosque in Boston and is affiliated with a Muslim group that critics say nurses grievances that can lead to extremism.

Several people who attended the Islamic Society of Boston mosque in Cambridge, Mass., have been investigated for Islamic terrorism, including a conviction of the mosque's first president, Abdulrahman Alamoudi, in connection with an assassination plot against a Saudi prince.

Its sister mosque in Boston, known as the Islamic Society of Boston Cultural Center, has invited guests who have defended terrorism suspects. A former trustee appears in a series of videos in which he advocates treating gays as criminals, says husbands should sometimes beat their wives and calls on Allah (God) to kill Zionists and Jews, according to Americans for Peace and Tolerance, an interfaith group that has investigated the mosques.

The head of the group is among critics who say the two mosques teach a brand of Islamic thought that encourages grievances against the West, distrust of law enforcement and opposition to Western forms of government, dress and social values.

"We don't know where these boys were radicalized, but this mosque has a curriculum that radicalizes people. Other people have been radicalized there," said the head of the group, Charles Jacobs.

Yusufi Vali, executive director at the Islamic Society of Boston Cultural Center, insists his mosque does not spread radical ideology and cannot be blamed for the acts of a few worshipers.

"If there were really any worry about us being extreme," Vali said, U.S. law enforcement agencies such as the FBI and Departments of Justice and Homeland Security would not partner with the Muslim American Society and the Boston mosque in conducting monthly meetings that have been ongoing for four years, he said, in an apparent reference to U.S. government outreach programs in the Muslim community.

The Cambridge and Boston mosques, separated by the Charles River, are owned by the same entity but managed individually. The imam of the Cambridge mosque, Sheik Basyouny Nehela, is on the board of directors of the Boston mosque.

Dzhokhar Tsarnaev and his brother, Tamerlan Tsarnaev, attended the Cambridge mosque for services and are accused of setting two bombs that killed three people and injured at least 264 others at the April 15 Boston Marathon.

The FBI has not indicated that either mosque was involved in any criminal activity, but mosque attendees and officials have been implicated in terrorist activity:

â?¢ Alamoudi, who signed the articles of incorporation as the Cambridge mosque's president, was sentenced to 23 years in federal court in Alexandria, Va., in 2004 for his role as a facilitator in what federal prosecutors called a Libyan assassination plot against then-crown prince Abdullah of Saudi Arabia. Abdullah is now the Saudi king.

â?¢ Aafia Siddiqui, who occasionally prayed at the Cambridge mosque, was arrested in Afghanistan in 2008 while in possession of cyanide canisters and plans for a chemical attack in New York City. She tried to grab a rifle while in detention and shot at military officers and FBI agents, for which she was convicted in New York in 2010 and is serving an 86-year sentence.

â?¢ Tarek Mehanna, who worshiped at the Cambridge mosque, was sentenced in 2012 to 17 years in prison for conspiring to aid al-Qaeda. Mehanna had traveled to Yemen to seek terrorist training and plotted to use automatic weapons to shoot up a mall in the Boston suburbs, federal investigators in Boston alleged.

â?¢ Ahmad Abousamra, the son of a former vice president of the Muslim American Society Boston Abdul-Badi Abousamra, was identified by the FBI as Mehanna's co-conspirator. He fled to Syria and is wanted by the FBI on charges of providing support to terrorists and conspiracy to kill Americans in a foreign country.

â?¢ Jamal Badawi of Canada, a former trustee of the Islamic Society of Boston Trust, which owns both mosques, was named as a non-indicted co-conspirator in the 2007 Holy Land Foundation terrorism trial in Texas over the funneling of money to Hamas, which is the Palestinian wing of the Muslim Brotherhood.

What both mosques have in common is an affiliation with the Muslim American Society, an organization founded in 1993 that describes itself as an American Islamic revival movement. It has also been described by federal prosecutors in court as the "overt arm" of the Muslim Brotherhood, which calls for Islamic law and is the parent organization of Hamas, a U.S.-designated terrorist group.

Critics say the Muslim American Society promotes a fraught relationship with the United States, expressed in part by the pattern discussed by Americans for Progress and Tolerance in which adherents are made to feel cut off from their home country and to identify with a global Islamist political community rather than with America.

Zuhdi Jasser, president of the American Islamic Forum for Democracy, said the radical teachings often follow a theme of recitation of grievances that Islam has with the West, advocacy against U.S. foreign policy and terrorism prosecutions, and efforts "to evangelize Islam in order to improve Western society that is secularized," he says.

Jasser, a veteran of the U.S. Navy and author of the 2012 book A Battle for the Soul of Islam: An American Muslim Patriot Fights to Save His Faith, says the teachings make some followers feel "like their national identity is completely absent and hollow, and that vacuum can be filled by (radical) Islamic ideology, which is supremacist and looks upon the West as evil."

The Cambridge mosque was founded in 1982 by students at the Massachusetts Institute of Technology, Harvard and several other Boston-area schools, according to a profile by the Pluralism Project at Harvard University. Its members founded the sister mosque in Boston in 2009.

The leadership of the two mosques is intertwined, and the ideology they teach is the same, Jacobs said. Ilya Feoktistov, director of research at Americans for Peace and Tolerance, said much of the money to create the Boston mosque came not from local Muslims but from foreign sources.

More than half of the $15.5 million used to found the Boston mosque came from Saudi sources, Feoktistov said, who cites financial documents that Jacobs' group obtained when the mosque sued it for defamation. The lawsuit was later dropped.

Vali said that the vast majority of total donors were in the United States and that "no donations were accepted if the donor wanted to have any decision-making influence (even if benign)."

Vali characterized Americans for Peace and Tolerance and its founder, Jacobs, as anti-Muslim activists who spread "lies and half-truths in order to attack and marginalize much of the local Muslim community and many of its institutions."

"It's the new McCarthyism in full swing," he said.

Sheik Basyouny Nehela, the imam of the Cambridge mosque, which is located across the Charles River from Boston, is on the board of directors for the Muslim American Society of Boston, which runs the Boston mosque. The Tsarnaevs attended the Cambridge mosque.

A statement issued by the Cambridge mosque said the Tsarnaev brothers were "occasional visitors." The mosque's office manager, Nichole Mossalam, said neither brother expressed radical views. "They never exhibited any violent sentiments or behaviors. Otherwise, they would have been reported," Mossalam said.

The Cambridge mosque said Tsarnaev, 26, who died Thursday night in a shootout with police, "disagreed with the moderate American-Islamic theology" of the mosque. Tsarnaev challenged an imam who said in his sermon that it was appropriate to celebrate U.S. national holidays and was told to stop such outbursts, the mosque said in a statement.

Talal Eid, a Muslim chaplain at Brandeis University, said focusing on individual radicals that prayed in a building is unfair.

"In 2011, the two brothers were right under the nose of the FBI and they didn't find anything," Eid said, who never met the Tsarnaevs. "How do you want me as an imam to know enough to tell them they are not welcome here? How can I figure out those people have that kind of criminal intent?"

The Muslim American Society says on its website that it is independent of the Muslim Brotherhood. However, early Brotherhood literature is considered "the foundational texts for the intellectual component for Islamic work in America," the website states.

Jacobs says claims of moderate Islam do not square with the mosque's classic jihadi texts in its library and its hosting of radical speakers.

Jacobs said Ahmed Mansour, his co-director at Americans for Peace and Tolerance, found writings by Syed Qutb, the former leader of the Muslim Brotherhood in Egypt, and other jihadi texts at the Cambridge mosque's library when Mansour went there in 2003. Qutb pioneered the radical violent ideology espoused by al-Qaeda.

Yusuf al Qaradawi, the Muslim Brotherhood spiritual leader who espouses radical views in videos collected by Jacobs' group, was listed as a trustee on the Cambridge mosque's IRS filings until 2000, and on the mosque's website until 2003, when he addressed congregants via recorded video message to raise money for the Boston mosque, according to a screenshot of the announcement that Feoktistov provided.

Vali said Qaradawi was listed as an honorary trustee years ago only because his scholarship and high esteem in Muslim circles would help with fundraising.

Yasir Qadhi, who lectured at the Boston mosque in April 2009, has advocated replacing U.S. democracy with Islamic rule and called Christians "filthy" polytheists whose "life and prosperity â?¦ holds no value in the state of Jihad," according to a video obtained by Jacobs' group.

Vali said Qadhi was a guest of a non-profit organization that was renting space at the Boston mosque and has changed his views since that video was made.

Jacobs and others say it is not only renters who express sympathetic views for terrorists. Leaders of the Boston and Cambridge mosques, and invited guests, have advocated on behalf of convicted terrorists, urging followers to seek their release or lenient sentences.

Imam Abdullah Faaruuq, sometimes a spokesman for the Boston mosque, used Siddiqui's case to speak against the USA Patriot Act, the anti-terrorism law passed under the George W. Bush administration. "After they're done with (Siddiqui), they are going to come to your door if they feel like it," he said, according to a video obtained by Americans for Peace and Tolerance.

Anwar Kazmi, a member of the Cambridge mosque's board of trustees, called for leniency for Mehanna and Siddiqui at a Boston rally in February 2012, in a video posted to YouTube. He characterized Siddiqui's 86-year sentence as excessive.

In an interview with USA TODAY, Kazmi insisted that the Cambridge mosque is moderate and condemns the marathon bombings. On Monday, the mosque e-mailed members to caution them that the FBI may question them and that they may want to seek representation.

"This kind of violence, terrorism, it's just completely contrary to the spirit of Islam," Kasmi said. "The words in the Quran say if anybody kills even a single human being without just cause, it's as if you've killed all of humanity."